[aerohead]

Originally Posted by 3-Wheeler

Hi Robert,

Yes, the idea is to give the air plenty of room to expand away from the body shape as it passes through the air.

The air under the car, unfortunately gets compressed and it not allowed room to move away from the body since the road is there. This compression takes energy and creates more air drag compared to all the other outside surfaces of the shape.

My tail is planned to be 48 inches long, unless I hear back from the DOT before hand.

Metro made his tail 51 inches I believe, and his results speak for themselves.

The overall car length will still be shorter than a typical short-bed pickup in length, so I'm going to go for it, and keep the full length!!

With the tail extension, I am looking for at least 90mpg results (at my typical speed). OK, maybe throw summer temps in there as well, for good measure.

Jim.

Jim,if you can compare the area at the back of your new tail to the area of the back of the Insight,it will give you an idea of your new Cd.The profile drag varies directly with wake area.